POSTOPERATIVE VAGINAL CUFF IRRADIATION USING HIGH-DOSE-RATE REMOTE AFTERLOADING - A PHASE-II CLINICAL PROTOCOL

Purpose: In September 1989, a postoperative Phase II high dose rate (H DR) brachytherapy protocol was started for International Federation of Gynecology and Obstetrics (FIGO) Stage I endometrial adenocarcinoma. This review reports the overall survival, local control, and complicat ion rates for the initial 63 patients treated in this Phase II study. Methods and Materials: High dose rate brachytherapy was delivered usin g an Iridium-192 HDR remote afterloader. Sixty-three patients were ent ered into the :Phase II protocol, each receiving two vaginal cuff trea tments 1 week apart (range 4-12 days) with vaginal ovoids (diameter 2. 0-3.0 cm). No patient received adjuvant external beam radiation. A dos e of 32.4 Gy in two fractions was prescribed to the ovoid surface in 6 3 patients. The first three patients treated at our institution receiv ed 15, 16.2, and 29 Gy, respectively, to determine acute effects. Resu lts: At a median follow-up of 1.6 years (range 0.75-4.3 years) no pati ent has developed a vaginal cuff recurrence. One regional recurrence ( 1.6%) occurred at 1.2 years at the pelvic side wall. This patient is a live and without evidence of disease 7 months after completion of salv age irradiation, which resulted in the only vaginal stenosis (1.6%). F ourteen patients (22%) experienced vaginal apex fibrosis by physical e xam, which was clinically symptomatic in four patients. Two patients r eported stress incontinence; however, these symptoms were noted prior to their HDR therapy. One patient died 2.4 years after HDR therapy due to cardiovascular disease without evidence of cancer at autopsy. Conc lusion: Preliminary results of our phase II HDR vaginal cuff protocol for postoperative FIGO Stage IA, Grade 3 or Stage IB, Grade 1-2 patien ts demonstrate that 32.4 Gy in two fractions is well tolerated by the vaginal cuff mucosa. Local control appears comparable to our prior exp erience and others with low dose rate (LDR) brachytherapy. Additional patient accrual and further follow-up will better determine the late m orbidity, local control, and overall survival of these patients.